At least two pairs of genes control eye color. Both pairs influence the production of the pigment, melanin, but act independently. One pair of alleles is B (Brown color; dominant) and b (blue color); the other pair is A (pigment production; dominant) and a (no pigment production; albino). The gene pair aais epistatic to (masks) B and b and produces the nonpigmented eyes of the albino. What is the typeof gene interaction that exists between the two gene pairs?

At least two pairs of genes control eye color. Both pairs influence the production of the pigment, melanin, but act independently. One pair of alleles is B (Brown color; dominant) and b (blue color); the other pair is A (pigment production; dominant) and a (no pigment production; albino). The gene pair aais epistatic to (masks) B and b and produces the nonpigmented eyes of the albino. What is the typeof gene interaction that exists between the two gene pairs?

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter15: Genomes And Genomics

Section: Chapter Questions

Problem 1QP: The gene controlling ABO blood type and the gene underlying nail-patella syndrome are said to show...

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Junctional epidermolysis bullosa (JEB) is a severe skin disorder that results in blisters over the entire body. The disorder is caused by autosomal recessive mutations at any one of three loci that help to encode laminin 5, a major component in the dermal–epidermal basement membrane. Leena Pulkkinen and colleagues described a male newborn who was born with JEB and died at 2 months of age (L. Pulkkinen et al. 1997. American Journal of Human Genetics 61:611–619); the child had healthy, unrelated parents. Chromosome analysis revealed that the infant had 46 normal-appearing chromosomes. Analysis of DNA showed that his mother was heterozygous for a JEB-causing allele at the LAMB3 locus, which is on chromosome 1. The father had two normal alleles at this locus. DNA fingerprinting demonstrated that the male assumed to be the father had, in fact, conceived the child. Q. Assuming that no new mutations occurred in this family, explain the presence of an autosomal recessive disease in the child…
Junctional epidermolysis bullosa (JEB) is a severe skin disorder that results in blisters over the entire body. The disorder is caused by autosomal recessive mutations at any one of three loci that help to encode laminin 5, a major component in the dermal–epidermal basement membrane. Leena Pulkkinen and colleagues described a male newborn who was born with JEB and died at 2 months of age (L. Pulkkinen et al. 1997. American Journal of Human Genetics 61:611–619); the child had healthy, unrelated parents. Chromosome analysis revealed that the infant had 46 normal-appearing chromosomes. Analysis of DNA showed that his mother was heterozygous for a JEB-causing allele at the LAMB3 locus, which is on chromosome 1. The father had two normal alleles at this locus. DNA fingerprinting demonstrated that the male assumed to be the father had, in fact, conceived the child. Q. How might you go about proving your explanation? Assume that a number of genetic markers are available for each chromosome.
1) Perception of a bitter taste from phenylthiocarbamide (PTC) is dominant (T) to not being able to taste PTC. Albinism is recessive to normal pigmentation (A). The genes controlling these traits are on separate chromosomes. a. A normally pigmented woman who cannot taste PTC has a father who is an albino taster, marries a many homozygous for normal pigmentation who is a PTC taster, but whose mother did not taste PTC. What are the genotypes of the woman and man listed here? b. Assuming the man and woman in the above section have children, what percentage of these children will be albino? c. What percentage of these children will have the same phenotype as their mother?
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In man, muscular dystrophy is a condition in which the muscles waste away during early life and may result in a shorter life expectancy. It is due to a sex-linked, recessive gene. A certain couple has five children – three boys (ages 1yr, 3yrs, and 10yrs old) and two girls (ages 5yrs and 7yrs old). The oldest boy shows the symptoms of this disease. You are their family physician and they come to you for advice. What would you tell them about the chances of their other children developing the disease?
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